1. Field of the Invention
The present invention relates to an apparatus for generating negative ions with which air can be ionized.
2. Description of the Prior Art
It has been known for a long time that air ions or ions in air greatly influence the health of a human body. Air ions are generated by electrolytic dissociation due to radioactive materials of the earth's crust, cosmic rays in the atmosphere, ultraviolet rays, gaseous oxidization due to heat, and electrolytic dissociation due to lightning discharge. They are also generated by electrification in air accompanied by water drop fission in air. Namely, electrification phenomena during precipitation and in the vicinity of water falls are called the "Lenard Effect" or "Water fall effect", and ions generated in air are negative ions regardless of the electric charge of water drops (Refer to "Atmospheric electrics", page 27, written by Naohisa Hatakeyama and Minoru Kawano and published by Iwanami Publishing Co., Ltd.).
In connection with influences upon human bodies due to positive and negative ions which are generated by electric dissociation of air, it is generally said that positive ions excite the nerves and negative ions tranquilize the nerves. For this reason, it is considered that negative ions generated in air at and around water falls, rivers, and sea shores refresh human bodies and minds.
In recent researches, it has been found that negative ions have a dust eliminating effect, sterilization effect, deordorization and gaseous constituents eliminating effects, and electrification preventing effect, and furthermore have favorable influences on the growth of animals and plants. And attention has been made to negative ions.
Conventionally, a negative ion generating apparatus in which positive and negative ions are generated by utilizing corona discharge and the positive ions are caught while the negative ions are extracted, has been used as a device for artificially generating negative ions. However, it has been found that, when this kind of a device is used, ozone and nitride oxide which are harmful to human bodies are generated as byproducts.
On the other hand, according to the Lenard Effect, it is possible to generate a comparatively large number of negative ions with a small electric power due to only fission of water drops, without generating any harmful materials nor further requiring electric power as necessary when corona discharge is utilized.
Lenard found out through experiments that, in a case where water drops are split when colliding with a metal plate, ions are generated in atmospheric air; the total quantity of electrification of the split water drops becomes larger than the electric quantity of the initial water drops; and the total quantity of electric charge of ions generated in air is equal to the quantity of electricity of the water drops increased through fission. However, thereafter, Simpson repeated Lenard's experiments, carried out measurements by using more accurate devices, and confirmed and reported that only fission of water drops in air brings the results similar to the case of Lenard's ; ions generated in air are negative ions regardless of the electric charge of the water drops; and the water drops have the positive electric charge which is equivalent to number of ions generated in fission ("Atmospheric electrics", pages 26 to 27, written by Hisanao Hatakeyama and Minoru Kawamoto and published by Iwanami Publishing Co., Ltd.).
A method to utilize the Lenard Effect is disclosed in Japanese Laid open Patent Publication No. Hei 4-141179 and No. Hei 5-31198. In the method described in these prior embodiments, in summary, microscopic water drops are formed and mixed with air to take out negative ions by selecting the particle size of the microscopic water drops mixed with air. The method described in the prior embodiments is basically based on the concept that a water jet stream is split or separated by bringing it into collision with a metallic plate. It is deemed that Lenard's experiments are faithfully repeated.
In regard to a mechanism with which ions are generated in air due to fission of water drops, it is explained as follows, in the electrostatic handbook, page 104, ("Electrostatics Academy", Ohm Publishing Co.); namely, in a case where phase .alpha. is gas (air) and phase .beta. is liquid (water), when high energy (jetting, collision and shedding) is given to water, electric double layers by H.sup.+, OH.sup.- due to ion dissociation of water is formed, and at the phase boundary, electric doublets are oriented to form double layers of electric dipole due to the electric dipole moment (6.17.times.10.sup.-3 Cm), wherein negative ions are oriented outwards. More negative ions are attracted near the liquid boundary, and positive ions are not pulled so strongly and freely in the liquid. Therefore, positive ions remain in the liquid and are neutralized through grounding. In the case where water drops are ultimately minimized by providing high energy such as jetting, collision, shedding and so on to water, when electric dipole is oriented on the surface of water drops, oxygen (O.sub.2) molecules which exist at the phase boundary at the gaseous (air) side are ionized and become groups of negative ions expressed with O.sub.2.sup.-.(H.sub.2 O)n. These groups of negative ion particles are defined as negative ion added water molecules.
According to the ion generating mechanism described above, it is found that air is ionized by providing high energy to water drops and splitting the water drops. Therefore, in Lenard's case, high energy is given to water drops by bringing water drops into collision with a metallic plate. However, according to Lenard's method employed in the prior embodiments, the energy given to water drops will be determined by the jetting pressure of water and the distance between water jetting nozzles and the metallic plate. So, a pump having a large output must be used to secure high pressure jetting with the distance between the nozzles and the metallic plate adequately maintained.
Japanese Laid Open Patent Publication No. Hei 4-141179 discloses an example of using an ultrasonic humidifier for the purpose of generating minute water drops. However, it is necessary to provide an ultrasonic generator having a high output capacity in order to give high energy to water drops by utilizing ultrasonic waves. Therefore, it can not be said that the ultrasonic humidifier is an effective means from the standpoint of negative ion generation ratio per unit power. As pointed out by Simpson, only fission of water drops in air may produce the same effect as that of Lenard's case.
It is therefore an object of the invention to provide an apparatus for generating negative ions by functionally making clear the mechanism of generating negative ions as much as possible and efficiently utilizing the functions thereof.
It is another object of the invention to provide an apparatus for generating a large amount of negative ions through gas and liquid separation after splitting liquid into minute water drops by utilizing the high energy of a turning air stream.
It is a further object of the invention to provide an apparatus for generating a large amount of negative ions by providing an ion dissociation treatment to the liquid to be split into minute water drops in advance. It is a still further object of the invention to provide an apparatus for splitting the liquid jetted into the turning air stream into micronized water drops by utilizing the centrifugal force generated by the turning air stream and causing a Coriolis force to act on the liquid drops.
It is a further object of the invention to provide an apparatus for jetting liquid into the turning air stream by causing air to flow along a helical portion of a screw guide arranged in a pneumatic feeding conduit and causing spiral movement to the air stream.
It is a further object of the invention to provide an apparatus for jetting liquid drops into the turning air stream by applying to the turning air stream the jetting liquid drops and providing the centrifugal force and Coriolis force to the liquid drops.